A bone-chilling polar vortex will bring a two-day cold snap to the city starting Thursday — making it feel like close to 0 degrees.

“The one positive about this is while the cold is going to be very intense, it’s going to be short-lived,” said senior Accuweather meteorologist Tom Kines. “We’re going on a roller-coaster ride in the temperature department over the next week.”

The mercury will swing 20 degrees between Thursday and Sunday — initially struggling to top 30 degrees before recovering to above-average temps by the end of the weekend.

Thursday will only get up to 28 degrees, and it will feel even worse due to a fierce wind chill that will shave off at least 20 degrees.

“Layer up,” Kines warned.

Friday won’t be much better even though the wind will die down. The high for the day is only forecast to be 26, which Kines said was unusually cold for the city this early in the season.

But he noted the brief polar vortex — a cold air mass that sits over Canada and occasionally moves south — would be far worse if it happened in the middle of winter when there was already snow on the ground.

The city will start thawing from the cold spell by Saturday, when temperatures get back to 40 degrees, the normal for the middle of December.

It will get even warmer Sunday with temps pushing 50 degrees.

Dangerous weather is already wreaking havoc on other parts of the country: